American Volt 2-pack Adjustable Electric Fan Thermostat Switch Mechanical Temperature Control 2-Pack adjustable fan thermostat w/ stainless probe sensor. Measures liquid or contact temperature and opens/closes switch. Flexible turn-on/turn-off temperature control range of 32'F to 248'F (0'C-120'C). Thermostat closes circuit at set temperature and sends power to your fan. Probe can be mounted in between radiator fins or inside inlet/outlet tube.